Recently there has been a marked increase in the frequency of incidences of skin cancer. This is caused in particular by the increasing trend towards intensive exposure to sunlight. The most frequent fatal skin disease is what is known as a malignant melanoma, which has an incidence in Central Europe of around 12 cases/100,000 people a year (Fortschritte der Medizin, Nr. 6, 2003—Progress in Medicine No. 6, 2003).
With early diagnosis of the skin disease and immediate initiation of therapy, which as a rule consists of the surgical removal of the diseased tissue, the prospects of recovery are good. The problem however is that of detecting the disease at an early stage.
Previously as a general rule an initial prophylactic examination of the skin was undertaken by a skin specialist. This initial examination is usually undertaken as a visual check using a magnifier. In such cases the skin specialist analyses deviations of the skin, such as pigment flecks. These are normally checked for asymmetry, border, color and diameter. An irregular and non-sharply defined skin deviation with mixed pigmentation and anametically observed growth tendency is a strong suspect for malignancy. Only if such a suspect area of skin is found in the first examination is it generally subjected to a closer analysis using examination methods with greater selectivity (e.g. incident light microscopy).
It is thus of decisive importance, for early detection of skin cancer, that suspect areas of the skin are securely detected in the first examination. This has previously been critical since a malignant melanoma is comparatively inconspicuous at the early stage and the quality of the initial examination thus greatly depends on the thoroughness and duration of the examination with which the skin specialist tracks down the suspect areas of skin. The conventional initial examination must also be undertaken by an experienced doctor and is comparatively time consuming. An efficient early detection of skin cancer is thus problematic and associated with high costs, especially in countries with a large land mass and a comparatively low density of doctors.
An aid designed to enable even unskilled personnel to conduct preliminary examinations for skin cancer is known from U.S. Pat. No. 5,369,527. The aid consists of a transparent, flexible plate, in which, in addition to the magnifier, there are markings made with which the diameter and the asymmetry of a skin mark can be determined.